The present invention relates generally to the field of storage systems for physical objects such as silicon wafers. More specifically, the present invention relates to the field of storage systems that permit storage of objects in an array of multiple rows and columns in a manner that facilitates ready access to objects positioned in more central regions of the array.
An efficient storage arrangement for certain physical objects is in an array of rows and columns. This type of array, however, presents the difficulty of how to easily access objects stored in central regions of the array using automated or semi-automated systems. If the rows and columns are positioned immediately adjacent to one another, automation systems cannot easily move between the closely spaced rows or columns. On the other hand, if the rows/columns are sufficiently spaced-apart to allow for an automation system to move between them, the total footprint of the storage system will be large and will thus increase the amount of facility space needed in order to house it. This, in turn, increases the cost of ownership of the storage system, particularly in fields such as in that of semiconductor manufacturing in which square footage within a fabrication facility is at a premium. It is thus desirable to provide a storage system that allows ready access to all objects stored in the system, without utilizing excessive amounts of physical space.
A storage system is disclosed which utilizes an array of at least three storage columns, each including a plurality of storage spaces. A primary automation system, which includes a robotic end effector for engaging objects to be stored, carrying objects into and removing objects from the storage spaces. A secondary automation system moves at least one of the storage columns as needed to create a travel space for the robotic end effector, thereby permitting ready access to all of the storage locations in the system.